In general, a reciprocating motor includes an outer stator and an inner stator which are disposed with a certain interval therebetween and a magnet frame having a magnet deposed between the outer stator and the inner stator, so that when power is applied to a winding coil wound around the stator, the magnet frame is linearly and reciprocally moved by an interaction of the stator and the magnet frame. The reciprocating motor is commonly used for a reciprocating compressor, and as its piston and the magnet frame are connected, the piston is reciprocally moved.
FIG. 1 is a sectional view of a conventional reciprocating motor, and FIG. 2 is a sectional view taken along line II-II of FIG. 1.
The conventional reciprocating motor includes an outer stator 104 in a cylindrical form with a plurality of thin lamination sheets laminated and a winding coil 102 wound therein, an inner stator 106 disposed at an inner circumferential surface of the outer stator 104 with a certain air gap therebetween and having a cylindrical form with a plurality of thin lamination sheets laminated, a magnet 108 disposed in a circumferential direction between the outer stator 104 and the inner stator 106, and a magnet frame 110, at which a plurality of the magnets 108 are fixed, being connected to a piston 118 to be reciprocally moved.
The piston 118 is disposed in a cylinder 120 and linearly and reciprocally moved according to the operation of the motor, compressing a fluid.
The outer stator 104 is supported by a support frame 124, and a support ring 114 is inserted at both sides thereof in order to maintain the cylindrical form.
Also, the inner stator 106 is fixed at an outer circumferential surface of the cylinder 120 by a press-fit method or an adhesive, and a support ring 116 is inserted at both sides of the inner stator 106 in order to support the plurality of lamination sheets.
The operation of the conventional reciprocating motor will now be described.
When power is applied to the winding coil 102, a flux is formed around the winding coil 102, forming a closed loop along the outer stator 104 and the inner stator 106. The magnet is linearly moved to an axial direction by the interaction of the flux formed between the outer stator 104 and the inner stator 106 and the flux formed by the magnet 108. When the direction of the electric current is changed alternately, the flux direction of the winding coil 102 is changed so that the magnet 108 is linearly and reciprocally moved.
According to the movement of the magnet 108, the magnet frame 110 to which the magnet 108 is fixed is linearly and reciprocally moved, and thus, the piston 118 is linearly and reciprocally moved.
However, the conventional art has a problem that because the inner stator 106 is fixed at the outer circumferential surface of the cylinder 120 by the press-fit method, the inner stator 106 is moved along with the magnet 108 in the axial direction by the vibration generated when the magnet 108 is moved reciprocally.
In addition, in the case that the inner stator 106 is fixed at the outer circumferential surface of the cylinder 120 by the adhesive and so on, an assembly operation is not easy.